The folk hero of ledgend who, in any given situation, takes the route of action that requires the most balls. Usually referred to in romantic situations in which one guy is trying to convince another to "take the ballsy road" so as to help him win over a girl and/or avoid being a total pussy.
Dude A: I can't do that man, It's too risky...
Dude B: Come on man! What would Ballsy McBallsington do!?
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"